Screen display device

ABSTRACT

Herein disclosed is a display controlling apparatus, comprising: data output units ( 140 ) to be electrically connectable to respective display apparatuses; an information inputting unit ( 110 ) to be operable to have inputted therein information to be required for said display apparatuses to display on screens; a controlling unit ( 120 ) for producing contents to be displayed by said display apparatuses from said information inputted by said information inputting unit; and a video memory ( 130 ) having stored therein said contents produced by said controlling unit, wherein said controlling unit ( 120 ) is operative to adjust the resolution of each of said contents to be displayed by said display apparatuses on the basis of the number of said display apparatuses electrically connected to said signal outputting units, and to output said contents to be displayed at said adjusted resolution by said display apparatuses through said data output units ( 140 ).

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a display controlling apparatus, andmore particularly to a display controlling apparatus for allowing imagesto be displayed by display apparatuses.

DESCRIPTION OF THE RELATED ART

As one of conventional display controlling apparatuses, there is wellknown a display controlling apparatus which is mounted on an automotivevehicle as allowing a display apparatus to display navigationinformation on, for example, a road map. In recent years, there havebeen proposed a wide variety of display controlling apparatuses of thistype one typical example of which is disclosed in Japanese PatentLaying-Open Publication No. H10-288528. The above mentioned conventionaldisplay controlling apparatus mounted on the automotive vehicle can beoperated by not only user who is at the front seat of the automotivevehicle, but also user who is at the rear seat of the automotivevehicle.

As shown in FIG. 11, the conventional display controlling apparatusdisclosed in Japanese Patent Laying-Open Publication No. H10-288528 isoperative to allow each of display apparatuses 12 and 14 to displayinformation obtained from information source 10. In this case, thecentral processing unit (CPU) 22 is operative to convert the informationobtained from the data source 10 to image data having layerscollectively defined as data structure, and to output the image data totwo video random access memories (VRAM) 24 and 26 on the basis of itsdata structure.

In general, the image data to be outputted to the display apparatuses 12and 14 is firstly stored in line buffers on scanning line basis. Theimage data stored in the line buffers is then converted to image signalssuch as for example RGB signal and NTSC signal. The converted imagesignals are then outputted to the respective display apparatuses. Theimages represented by the image signals are then displayed on therespective screens of the display apparatuses.

The conventional display controlling apparatus thus constructed aspreviously mentioned, however, encounters such a problem that theconventional display controlling apparatus is large and complicated inconstruction by reason that the image signals to be outputted to thedisplay apparatuses are respectively produced by the controlling unitseach comprises VRAM, line buffer, and other elements.

It is, therefore, an object of the present invention to provide adisplay controlling apparatus which can be simple in constructionwithout being affected by the number of the display apparatuses.

DISCLOSURE OF THE INVENTION

In accordance with a first aspect of the present invention, there isprovided a display controlling apparatus, comprising: data output unitsto be electrically connectable to respective display apparatuses; aninformation inputting unit to be operable to have inputted thereininformation to be required for the display apparatuses to display onscreens; a controlling unit for producing contents to be displayed bythe display apparatuses from the information inputted by the informationinputting unit; and a video memory having stored therein the contentsproduced by the controlling unit, wherein the controlling unit isoperative to output the contents stored in the video memory to thedisplay apparatuses through the data output units.

The display controlling apparatus thus constructed as previouslymentioned can allow the images to be respectively displayed by thedisplay apparatuses by reason that the controlling unit is operative toallow the images to be displayed by the display apparatuses bycontrolling the video memory and the signal outputting unitselectrically connected to the display apparatuses.

In the display controlling apparatus according to the present invention,the controlling unit may be operative to adjust the resolution of eachof the contents to be displayed by the display apparatuses on the basisof the number of the display apparatuses electrically connected to thesignal outputting units, and to output the contents to be displayed atthe adjusted resolution by the display apparatuses through the dataoutput units. On the other hand, the controlling unit may be operativeto maintain the resolution of each of the contents to be displayed bythe display apparatuses when the judgment is made that the number of thedisplay apparatuses is equal to one.

The display controlling apparatus thus constructed as previouslymentioned can effectively utilize the capacity of the video memory byreason that the controlling unit is operative to adjust the resolutionof each of the contents to be displayed by the display apparatuses onthe basis of the number of the display apparatuses electricallyconnected to the signal outputting units.

In accordance with a second aspect of the present invention, there isprovided a display controlling apparatus, comprising: data output unitsto be electrically connectable to respective display apparatuses; aninformation inputting unit to be operable to have inputted therein datato be required for the display apparatuses to display on screens; acontrolling unit for producing image data on contents to be displayed bythe display apparatuses on the basis of the information inputted by theinformation inputting unit; and a video memory having stored therein theimage data produced by the controlling unit, wherein the controllingunit is operative to output the contents to the display apparatusesthrough the data output units on the basis of the image data stored inthe video memory.

The display controlling apparatus thus constructed as previouslymentioned can allow the images to be respectively displayed by thedisplay apparatuses by reason that the controlling unit is operative toallow the images to be respectively displayed by the display apparatusesby controlling the video memory and the signal outputting unitselectrically connected to the display apparatuses.

In the display controlling apparatus according to the present invention,the image data may have layers to be collectively defined as datastructure. Each of the contents to be displayed by the displayapparatuses may be constituted by data assigned to one or more of thelayers.

The display controlling apparatus thus constructed as previouslymentioned can easily produce the image from the data stored in the videomemory on the basis of the layers of the data stored in the video memoryin response to an instruction to each of the display controllingapparatus to produce the image to be displayed on the screen.

In the display controlling apparatus according to the present invention,the controlling unit may be operative to allow the contents to besequentially received by the display apparatuses through the data outputunits in order of the data output units electrically connected to thedisplay apparatuses in a period of a synchronization signal.

The display controlling apparatus thus constructed as previouslymentioned can sequentially output the contents stored in the videomemory to the display apparatuses in order of the signal outputtingunits electrically connected to the display apparatuses by switching thecontents to be outputted to the display apparatuses on the basis of theperiod of the synchronization signal.

In the display controlling apparatus according to the present invention,the number of the display apparatuses electrically connected to the dataoutput units may be equal to two. The controlling unit may be operativeto allow the contents to be received by one of the two displayapparatuses on each of leading edges of the synchronization signal, andto allow the contents to be received by the other of the two displayapparatuses on each of trailing edges of the synchronization signal.

The display controlling apparatus thus constructed as previouslymentioned can allow the image data to be received by one of the twodisplay apparatuses on each of leading edges of the synchronizationsignal, and to allow the image data to be received by the other of thetwo display apparatuses on each of trailing edges of the synchronizationsignal.

In the display controlling apparatus according to the present invention,each of the display apparatuses electrically connected to the dataoutput units may have an operating unit for issuing an instruction tothe controlling unit to select one or more contents. The controllingunit may be operative to judge whether or not one or more contentsselected by one of the display apparatuses are the same as one or morecontents which are being outputted to the other of the displayapparatuses, and to allow one of the display apparatuses to displayinformation on whether or not one or more contents selected by one ofthe display apparatuses are the same as one or more contents which arebeing outputted to the other of the display apparatuses in response tothe instruction issued by the operating unit of one of the displayapparatuses.

When the judgment is made that one or more contents selected by one ofthe display apparatuses are the same as one or more contents which arebeing outputted to the other of the display apparatuses, the displaycontrolling apparatus thus constructed as previously mentioned canproduce information that one or more contents selected by one of thedisplay apparatuses are the same as one or more contents which are beingoutputted to the other of the display apparatuses, and to allow theinformation to be displayed by one of the display apparatuses.

In the display controlling apparatus according to the present invention,each of the display apparatuses electrically connected to the dataoutput units has an operating unit for issuing an instruction to thecontrolling unit to select one or more contents. The controlling unitmay be operative to judge whether or not one or more contents selectedby one of the display apparatuses are the same as one or more contentswhich are being utilized through the operating unit to the other of thedisplay apparatuses, and to allow one of the display apparatuses todisplay information on whether or not one or more contents selected byone of the display apparatuses are the same as one or more contentswhich are being outputted to the other of the display apparatuses inresponse to the instruction issued by the operating unit of one of thedisplay apparatuses.

The display controlling apparatus thus constructed as previouslymentioned can allow the contents displayed by one of the displayapparatuses, and to be utilized by the user with the restriction on theuse of the contents by having one of the display apparatuses display theinformation that one or more contents selected by one of the displayapparatuses are the same as one or more contents which are beingoutputted to the other of the display apparatuses.

In the display controlling apparatus according to the present invention,the information displayed by one of the display apparatuses may berepresented by a pointer.

The display controlling apparatus thus constructed as previouslymentioned can improve the usability of the apparatus by allowing thepointer to be displayed on the screen, and to point the operation to beperformed by the display apparatus.

In the display controlling apparatus according to the present invention,the controlling unit may be operative to allow one or more contents tobe utilized through one of the display apparatuses with the restrictionon the use of the contents after allowing one of the display apparatusesto display the information that one or more contents selected by one ofthe display apparatuses are the same as one or more contents which arebeing outputted to the other of the display apparatuses.

When one or more contents selected by one of the display apparatuses arethe same as one or more contents which are being outputted to the otherof the display apparatuses, the display controlling apparatus thusconstructed as previously mentioned can allow one or more contents to becontinuously utilized through the other of the display apparatuses byallowing one or more contents to be utilized through one of the displayapparatuses with the restriction on the use of the contents.

In the display controlling apparatus according to the present invention,each of the display apparatuses may have an operating unit for issuingan instruction to the controlling unit to output one or more contents,the display apparatuses being assigned to respective priority sequences.The controlling unit may be operative to judge whether or not one ormore contents which are being outputted to one of the displayapparatuses are the same as one or more contents selected by the otherof the display apparatuses before judging whether or not one of thedisplay apparatuses exceeds in priority sequence the other of thedisplay apparatuses when the judgment is made that one or more contentsselected by the other of the display apparatuses are the same as one ormore contents which are being outputted to one of the displayapparatuses. The controlling unit may be operative to allow the other ofthe display apparatuses to display one or more contents the same as oneor more contents which are being outputted to one of the displayapparatuses with the restriction on the utilization of the contents whenthe judgment is made that one of the display apparatuses exceeds inpriority sequence the other of the display apparatuses.

The display controlling apparatus thus constructed as previouslymentioned can differentially permit the contents to be utilized by theusers through the display apparatuses on the basis of the prioritysequence of the display apparatuses.

In the display controlling apparatus according to the present invention,the controlling unit may be operative to allow the priority sequenceassigned to each of the display apparatuses to be changeable by one ormore operating units of the display apparatuses.

The display controlling apparatus thus constructed as previouslymentioned can improve the usability of the apparatus by allowing thepriority sequence of the display apparatuses to be changed by one ormore users.

In accordance with a third aspect of the present invention, there isprovided a display controlling apparatus for allowing displayapparatuses to display respective images represented by image data,comprising: a multiplexing unit for multiplexing the image dataindicative of the images to be displayed by the display apparatuses; abuffer memory having stored therein the multiplexed image data; anddemultiplexing unit for demultiplexing the multiplexed image data storedin the buffer memory to output the demultiplexed image data to each ofthe display apparatuses.

The display controlling apparatus thus constructed as previouslymentioned can allow the images to be respectively displayed by thedisplay apparatuses by having the buffer memory store the multiplexedimage data.

The display controlling apparatus according to the present invention mayfurther comprises a synchronization signal producing unit for producinga synchronization signal to be constituted by a pulse string having apredetermined period. The demultiplexing unit may be operative todemultiplex the multiplexed image data stored in the buffer memory byallowing the multiplexed image data to be selectively received by eachof the display apparatuses in the predetermined period of thesynchronization signal.

The display controlling apparatus according to the present invention mayfurther comprises a synchronization signal producing unit for producinga synchronization signal to be constituted by a pulse string having apredetermined period. The demultiplexing unit may be operative todemultiplex the multiplexed image data stored in the buffer memory byallowing the multiplexed image data to be received by one of the twodisplay apparatuses on each of leading edges of the synchronizationsignal, and to be received by the other of the two display apparatuseson each of trailing edges of the synchronization signal.

The display controlling apparatus thus constructed as previouslymentioned can allow the images to be displayed by the displayapparatuses by allowing the multiplexed image data to be demultiplexedat the predetermined period of the synchronization signal.

In the display controlling apparatus according to the present invention,the multiplexing unit may be operative to adjust the resolution of eachof the images to be respectively displayed by the display apparatuses onthe basis of the number of the display apparatuses electricallyconnected to the data output units to multiplex image data indicative ofthe images to be respectively displayed by the display apparatuses atthe adjusted resolution.

In the display controlling apparatus according to the present invention,the multiplexing unit may be operative to adjust the resolution of eachof the images to be respectively displayed by the display apparatuses ininverse proportional relationship with the number of the displayapparatuses electrically connected to the data output units.

The display controlling apparatus thus constructed as previouslymentioned can prevent the information on the contents stored in thevideo memory from being increased in proportion to the number of thedisplay apparatuses by adjusting the volume of the information to beoutputted to each of the display apparatuses on the basis of the numberof the display apparatuses even if two or more of the data output unitsare eclectically connected to the respective display apparatuses.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the display controlling apparatusaccording to the present invention will be more clearly understood fromthe following description taken in conjunction with the accompanyingdrawings:

FIG. 1 is a functional diagram showing the display controlling apparatusaccording to the first embodiment of the present invention;

FIG. 2 is a hardware diagram showing the display controlling apparatusaccording to the first embodiment of the present invention;

FIG. 3 is a schematic diagram showing an operation to be performed bythe display controlling apparatus according to the first embodiment ofthe present invention;

FIG. 4 is a schematic diagram showing an operation to be performed at ahalf resolution by the display controlling apparatus according to thefirst embodiment of the present invention;

FIG. 5 is a schematic view showing images displayed by the displayapparatuses provided with front and rear seats of an automotive vehicle;

FIG. 6 is a schematic view showing images displayed by the displayapparatuses provided with front and rear seats of an automotive vehicle;

FIG. 7 is a schematic view showing images displayed by the displayapparatuses provided with front and rear seats of an automotive vehicle;

FIG. 8 is a functional diagram showing the display controlling apparatusaccording to the second embodiment of the present invention;

FIG. 9 is a flowchart showing an operation of the display controllingapparatus according to the second embodiment of the present invention;

FIG. 10 is a schematic view showing images displayed by the displayapparatuses provided with front and rear seats of an automotive vehicle;and

FIG. 11 is a block diagram showing the conventional display controllingapparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The first to third embodiments of the display controlling apparatusaccording to the present invention will be described hereinafter inaccordance with accompanying drawings.

First Embodiment

The display controlling apparatus 100 according to the first embodimentof the present invention is shown in FIG. 1 as comprising data outputunits 140 and 141 to be electrically connectable to respective displayapparatuses, an information inputting unit 110 to be operable to haveinputted therein information to be required to display on screens of thedisplay apparatuses, a controlling unit 120 for producing contents to bedisplayed by the display apparatuses on the basis of the informationinputted by the information inputting unit 110, a video memory(hereinafter simply referred to as “VRAM” (Video Random Access Memory))130 having stored therein the contents produced by the controlling unit120. The controlling unit 120 is operative to output the contents storedin the video memory 130 to the display apparatuses through the dataoutput units 140 and 141 to ensure that the contents produced by thecontrolling unit 120 are displayed by the display apparatuses.

As sown in FIG. 1, the information inputting unit 110 is operative toallow the controlling unit 120 to receive the data of a road map, thedata of an operating panel, and other image data (these data being shownas images and others in FIG. 1).

Here, the controlling unit 120 may be operative to produce data to berequired to produce the contents (hereinafter simply referred to as“drawing data”), and to store the drawing data in the VRAM 130. Thedrawing data produced by the controlling unit 120 on the basis of theinformation inputted by the information inputting unit 110 may havelayers collectivelly defined as “data structure”. The controlling unit120 may be operative to produce each of the contents to be displayed bythe display apparatuses from the data assigned to one or more layers.The controlling unit 120 is operative to output data with respect toeach of frames (hereinafter simply referred to as “frame data”) of eachof the contents to be displayed by the display apparatuses in order ofthe display apparatuses on frame basis to the data output units 140 and141.

As shown in FIG. 2, the display controlling apparatus 100 according tothe first embodiment of the present invention may be constituted byspecific elements. As an example, the information inputting unit 110 isconstituted by an input and output interface device (shown as “I/O” inFIG. 2) 111 and a digital versatile disc (DVD) driving device 112. Theinformation inputting unit 110 is operative to receive data from the DVDdriving device 112 through the input and output interface device 111,and to output the data to the controlling unit 120. Here, the displaycontrolling apparatus 100 according to the present invention may beconstituted as part of a navigation apparatus to be mounted on anautomotive vehicle. The information inputting unit 110 of the displaycontrolling apparatus 100 constituted as part of the navigationapparatus may be operative to receive information on road map andnavigation menu from the DVD driving device 112 through the input andoutput interface device 111. Additionally, the input and outputinterface device 111 may be electrically connected to a hard diskdriving device and a video camera. The information inputting unit 110may be operative to receive information on the contents from each of thehard disk driving device and the video camera through the input andoutput interface device 111, and to output the information on thecontents to the controlling unit 120.

As shown in FIG. 2, the controlling unit 120 includes a drawingprocessor 121 for processing the data on images, a central processingunit (CPU) 122 for processing the data on control, a program read onlymemory (program ROM) 123 having stored therein a predetermined programto be executed by the drawing processor 121 or the CPU 122, a randomaccess memory (RAM) 124, a backup RAM 125 to be provided as a memoryhaving stored therein backup data, and a font ROM 126 to be provided asa memory having stored therein the data of font to be required toproduce the contents.

Here, the drawing processor 121 may be constituted by a large scaleintegrated (LSI) circuit device. The drawing processor 121 may beoperative to receive the control program and data from the program ROM123, the DRAM 124, the font ROM 126, and other memory media through theCPU 122, and to process the data on the basis of the received controlprogram. The drawing processor 121 is operative to produce the framedata to be outputted in synchronization with a synchronization signal tothe display apparatuses 140 and 141. As shown in FIG. 2, the data outputunits 140 and 141 may be collectively constituted by a line buffer 140.Additionally, the line buffer may be constituted by part of the drawingprocessor 121.

As shown in FIG. 3, the drawing data produced by the drawing processor121 has layers collectively defined as data structure. Accordingly, thedata assigned to each of the layers (for example, L1 to L8 shown in FIG.3) is stored in the VRAM 130 to form an imaginary block defined in amemory space. The drawing processor 121 is then operated to produce theframe data on the contents to be displayed by the first displayapparatus from the layers L1, L4, L5, L7, and L8 of the drawing datastored in the VRAM 130, and to produce the frame data on the contents tobe displayed by the second display apparatus from the layers L2, L3, L6,and L8 of the drawing data stored in the VRAM 130. The drawing processor121 is then operated to allow the line buffer 140 to receive the framedata to be outputted to the first display apparatus and the frame datato be outputted to the second display apparatus on a predeterminedtiming.

Here, the drawing processor 121 may be operative to determine theresolution of each of the contents to be displayed by the displayapparatuses on the basis of the number of the display apparatuses, andto store the image data indicative of the contents to be displayed atthe determined resolution in the line buffer 140. More specifically, thedrawing processor 121 may be operative to reduce the resolution of eachof the contents to be displayed by the display apparatuses to one-halfwhen the judgment is made that two of the data output units areelectrically connected to respective display apparatuses, and to reducethe resolution of each of the contents to be displayed by the displayapparatuses to one-third when the judgment is made that three of thedata output units are electrically connected to respective displayapparatuses.

The following description will be then directed to the case that each ofthe contents to be displayed by the display apparatuses at theresolution reduced to one-half is produced from the data assigned to oneor more layers. As shown in FIG. 4, each of the layers has two parts,one of the two parts being defended as a block assigned to the data tobe outputted to the first display apparatus, the other of the two partsbeing defended as a block assigned to the data to be outputted to thesecond display apparatus. As two parts of each of the layers L1, L3, L6,and L7, the layer L1 has two parts L1 a and L1 b, the layer L3 havingtwo parts L3 a and L3 b, the layer L6 having two parts L6 a and L6 b,and the layer L7 having two parts L7 a and L7 b.

Here, the resolution of each of the contents to be displayed by thedisplay apparatuses may be maintained without being reduced by thecontrolling unit 120 when the judgment is made that any one of the dataoutput units is electrically connected to only one display apparatus.

FIGS. 5 to 7 are respectively schematic views each showing imagesdisplayed on screens of the display apparatuses provided with thedisplay controlling apparatus built in an automotive vehicle, one of thedisplay apparatuses being provided with a front seat of the automotivevehicle, the other of the display apparatuses being provided with rearseat of the automotive vehicle. The navigation menu assigned to thelayer 1, the left road map assigned to the layer 2, and the right roadmap assigned to the layer 3 are synthesized and displayed on the screenof the display apparatus provided with the front seat. The navigationmenu assigned to the layer 1, the left road map assigned to the layer 4,the right road map assigned to the layer 5, and an on-screen informationassigned to the layer 9 is displayed on the screen of the displayapparatus provided with the front seat. Here, the term “on-screeninformation” is intended to indicate specific message to be displayed onthe screen of the display apparatus.

As shown in FIG. 6, the two images are displayed on the respectivescreens of the display apparatuses provided with the front and rearseats of the automotive vehicle. The navigation menu assigned to thelayer 1, the left road map assigned to the layer 2, and the right roadmap assigned to the layer 3 are collectively displayed on the screen ofthe display apparatus provided with the front seat. On the other hand,the navigation menu assigned to the layer 1, the left road map assignedto the layer 2, the right road map assigned to the layer 3, and theon-screen information assigned to the layer 9 is displayed on the screenof the display apparatus provided with the rear seat. As will be seenform FIG. 6, the image data (of the layers 1, 2, and 3) is shared by thetwo display apparatuses.

As shown in FIG. 7, the two images are schematically displayed on therespective screens of the display apparatuses provided with the frontand rear seats of the automotive vehicle. The image displayed on thescreen of the display apparatus provided with the front seat isindicative of the information on a multi-function interface “audio”assigned to the layer 4. On the other hand, the image displayed on thescreen of the display apparatus provided with the rear seat isindicative of the information on a multi-function interface “weatherforecast” assigned to the layer 5. In this embodiment, the informationon the multi-function interfaces “audio” and “weather forecast” arerespectively displayed on the screens of the display apparatusesprovided with the front and rear seats of the automotive vehicle.However, the information on the multi-function interfaces may includeother audio and images to be displayed by the display apparatuses.

The above mentioned frame data is outputted to the display apparatusesby the line buffer 140 on a predetermined timing. Here, the line buffer140 is operated to switch to the frame data on the contents to bedisplayed by the display apparatus and the frame data on the contents tobe displayed by the display apparatus on the basis of a period of asynchronization signal. When the judgment is made that the three dataoutput units are electrically connected to the three displayapparatuses, the line buffer 140 may be operative to sequentially outputthe frame data on the contents to be displayed by the first displayapparatus, the frame data on the contents to be displayed by the seconddisplay apparatus, the frame data on the contents to be displayed by thethird display apparatus in order of the three display apparatuses on thebasis of the period of the synchronization signal.

Additionally, the signal controlling unit may be operative to allow thecontents stored in the video memory to be received by one of the twodisplay apparatuses on each of leading edges of the synchronizationsignal, and to output each of the contents stored in the video memory tothe other of the two display apparatuses on each of trailing edges ofthe synchronization signal when the judgment is made that there are twodisplay apparatuses each electrically connected to any one of the dataoutput units.

In this embodiment, the display controlling apparatus 100 comprises aline buffer 140, the display controlling apparatus may comprise two ormore line buffers which are electrically connected to the respectivedisplay apparatuses to allow the contents to be received by therespective display apparatuses.

From the above detail description, it will be understood that thedisplay controlling apparatus according to the first embodiment of thepresent invention can prevent the information on the contents stored inthe video memory from being increased in proportion to the number of thedisplay apparatuses by adjusting the volume of the information to beoutputted to each of the display apparatuses on the basis of the numberof the display apparatuses even if two or more of the data output unitsare eclectically connected to the respective display apparatuses byreason that the controlling unit is operative to produce the images tobe displayed by the display apparatuses from the data stored in thevideo memory.

The display controlling apparatus according to the first embodiment ofthe present invention can effectively utilize the video memory by reasonthat the controlling unit is operative to adjust the resolution of eachof the contents to be displayed by the display apparatuses on the basisof the number of the display apparatuses electrically connected to thesignal outputting units.

The display controlling apparatus according to the first embodiment ofthe present invention can easily produce the contents from the datastored in the video memory on the basis of the layers of the data storedin the video memory in response to an instruction to each of the displaycontrolling apparatus to produce the contents to be displayed on thescreen.

The display controlling apparatus according to the first embodiment ofthe present invention can sequentially output the contents stored in thevideo memory to the display apparatuses in order of the signaloutputting units electrically connected to the display apparatuses byswitching the contents to be outputted to the display apparatuses on thebasis of the period of the synchronization signal, and to allow theimages to be displayed on the respective screens by the displayapparatuses on the basis of the contents at the same time.

The display controlling apparatus according to first embodiment of thepresent invention can allow the contents stored in the video memory tobe received by one of the two display apparatuses on each of leadingedges of the synchronization signal, and to output each of the contentsstored in the video memory to the other of the two display apparatuseson each of trailing edges of the synchronization signal when thejudgment is made that there are two display apparatuses eachelectrically connected to any one of the data output units.

Second Embodiment

The second embodiment of the display controlling apparatus according tothe present invention will be then described hereinafter with referenceto FIG. 8.

As shown in FIG. 8, the display controlling apparatus 200 according tothe second embodiment of the present invention is operative to outputimage data to two display apparatuses 201 and 202 to have the displayapparatuses 201 and 202 to display respective images to be displayed onthe screens by the display apparatuses 201 and 202. In this embodiment,the display controlling apparatus 200 shown in FIG. 8 is operative tooutput image data to two display apparatuses 201 and 202. However, thedisplay controlling apparatus according to the present invention may beoperative to output image data to three or more display apparatuses.

The display controlling apparatus 200 comprises a drawing data producingunit 210 for producing drawing data indicative of images to be displayedon respective screens of the display apparatuses 201 and 202, a videorandom access memory (VRAM) 211 having stored therein the drawing dataproduced by the drawing data producing unit 210, a multiplexing unit 212for multiplexing the drawing data stored in the VRAM 211, a buffermemory 213 for buffering the drawing data multiplexed by themultiplexing unit 212, a demultiplexing unit 214 for demultiplexing thedrawing data to be outputting to the display apparatuses 201 and 202,and a synchronization signal producing unit 215 for producing asynchronization signal having a periodic pulse string.

The drawing data producing unit 210 is operative to produce the drawingdata of a road map, the drawing data of an operating panel, and otherdrawing data such as for example an image and a text, and to output thedrawing data to the VRAM 211.

The multiplexing unit 212 is operative to multiplex the drawing data onthe images to be displayed by the display apparatuses 201 and 202 bysequentially and selectively receiving the drawing data from the VRAM211 on scanning line basis or pixel basis.

Here, the multiplexing unit 212 may be operative to selectively receivethe drawing data from the VRAM 211 on pixel basis in order of the signaloutputting units electrically connected to the display apparatuses 201and 202. The multiplexing unit 212 may be operative to selectivelyreceive the drawing data from the VRAM 211 on scanning line of each ofthe display apparatuses 201 and 202.

The multiplexing unit 212 is operative to determine the resolution ofeach of the images to be displayed on the respective screens of thedisplay apparatuses 201 and 202 on the basis of the number of thedisplay apparatuses 201 and 202. More specifically, the multiplexingunit 212 is operative to determine the resolution of each of the imagesto be displayed on the respective screens of the display apparatuses 201and 202 in inverse proportion to the number of the display apparatuses201 and 202.

The buffer memory 213 is operative to output the drawing data to each ofthe display apparatuses 201 and 202 on a respective timing by bufferingthe drawing data to be outputted to each of the display apparatuses 201and 202.

The demultiplexing unit 214 is operative to demultiplex the multiplexeddata by allowing the multiplexed data to be sequentially received by thedisplay apparatuses 201 and 202 in order of the display apparatuses 201and 202.

More specifically, the demultiplexing unit 214 is operative todemultiplex the multiplexed data by switching the display apparatuses201 and 202 on the basis of the period of the synchronization signal.Additionally, the demultiplexing unit 214 is operative to allow themultiplexed data to be received by one of the display apparatuses 201and 202 on each of leading edges of the synchronization signal, and toallow the multiplexed data to be received by the other of the displayapparatuses 201 and 202 on each of trailing edges of the synchronizationsignal.

The display controlling apparatus 200 thus constructed as previouslymentioned is substantially the same in construction as the displaycontrolling apparatus 100 according to the first embodiment of thepresent invention. As shown in FIG. 2, the I/O 111 and the CPU 122 arecollectively constituted by the drawing data producing unit 210. TheVRAM 130 is replaced by the VRAM 211. The drawing processor 121 isconstituted by the multiplexing and demultiplexing units 212 and 214.The buffer memory 213 is replaced by the line buffer 140. Thesynchronization signal producing unit 215 is constituted by the CPU 122.

The operation of the display controlling apparatus 200 thus constructedas previously mentioned will be then described hereinafter withreference to FIG. 9. In this embodiment, the drawing data is producedand stored in the VRAM 211 by the drawing data producing unit 210, whilethe drawing data stored in the VRAM 211 is demultiplexed and outputtedto the display apparatuses 201 and 202.

The resolution of the drawing data stored in the VRAM 211 is determinedby the demultiplexing unit 212 on the basis of the number of the displayapparatuses 201 and 202 (in the step S20). The drawing data in which theresolution is determined by the demultiplexing unit 212 is multiplexed(in the step S21) and stored in the buffer memory 213 by thedemultiplexing unit 212 (in the step S22).

The demultiplexing unit 214 is operated to detect each of the leadingedges of the synchronization signal and each of the trailing edges ofthe synchronization signal (in the step S23), and to switch between thedrawing data to be outputted to one of the display apparatuses 201 and202 and the drawing data to be outputted to the other of the displayapparatuses 201 and 202 on the basis of the leading edges and each ofthe trailing edges of the synchronization signal (in the step S24).

When, on the other hand, the judgment is made that the synchronizationsignal is not detected by the CPU 122, the drawing data is not switchedby the CPU 122.

The multiplexed drawing data stored in the buffer memory 213 isselectively outputted to the display apparatuses 201 and 202 by thedemultiplexing unit 214 (in the step S25).

From the above detail description, it will be understood that thedisplay controlling apparatus 200 according to the second embodiment ofthe present invention can have the display apparatuses display images onthe respective screens by reason that the multiplexing unit is operativeto multiplex the drawing data to store the multiplexed drawing data inthe buffer memory 213.

The display controlling apparatus 200 according to the second embodimentof the present invention can allow the images to be displayed by thedisplay apparatuses at the same time by demultiplexing the multiplexeddata on the basis of the predetermined period. The display controllingapparatus thus constructed as previously mentioned can prevent theinformation on the contents stored in the buffer memory 213 from beingincreased in proportion to the number of the display apparatuses byadjusting the volume of the information to be outputted to each of thedisplay apparatuses on the basis of the number of the displayapparatuses even if two or more of the data output units areeclectically connected to the respective display apparatuses.

Third Embodiment

The display controlling apparatus according to the third embodiment ofthe present invention is operative to judge whether or not to allow thecontents to be displayed by the display apparatuses on the basis of thejudgment on whether or not the automotive vehicle is moving, and toperform the restricted operation by having the display apparatusesdisplay predetermined images when the judgment is made that theautomotive vehicle is moving. The constitutional elements of the displaycontrolling apparatus according to the third embodiment aresubstantially the same as those of the display controlling apparatus 100according to the first embodiment. Therefore, the constitutionalelements of the display controlling apparatus according to the thirdembodiment the same as those of the display controlling apparatus 100according to the first embodiment will not be described but bear thesame reference numerals and legends as those of the display controllingapparatus 100 according to the first embodiment.

The following description will be firstly directed to the case that theoperation is performed by the display controlling apparatus 100 on thebasis of the contents required for the display apparatuses to display onthe screens. The display controlling apparatus 100 is operative to judgewhether or not the contents selected by the display apparatus providedwith the front seat of the automotive vehicle (hereinafter simplyreferred to as “first display apparatus”) are the same as the contentswhich are being displayed on the screen of the display apparatusprovided with the rear seat of the automotive vehicle (hereinaftersimply referred to as “second display apparatus”), and to allow thefirst display apparatus to display the information on whether or not thecontents selected by the first display apparatus are the same as thecontents which are being displayed on the screen of the second displayapparatus.

The above mentioned operation of the display controlling apparatus 100according to the third embodiment of the present invention will bedescribed hereinafter with reference to FIG. 10. As shown in each ofFIGS. 10(a) and 10(b), two images displayed by the respective displayapparatuses provided with the front and rear seats of the automotivevehicle are indicative of the contents to be watched and utilized by theusers. Here, each of the display apparatuses may be operative to allowits operating unit to be operated by the user by displaying an imageindicative of functions of the operating unit. The display controllingapparatus 100 may be operative to output the contents to the displayapparatuses in response to an instruction issued through the operatingunit of each of the display apparatuses. As shown in FIG. 10(a), thenavigation information is displayed on the screen of the displayapparatus provided with the front seat. On the other hand, themultifunctional interface is displayed on the screen of the displayapparatus provided with the rear seat.

As will be seen from FIG. 10, the display controlling apparatus 100 isoperated to display, as a message to the user, the information about thefact that the multifunctional interface selected by one of the displayapparatuses (i.e., the display apparatus provided with the front seat inthis case) is the same as the contents which are being displayed on thescreen of the other of the display apparatuses (i.e., the displayapparatus provided with the rear seat in this case) when the judgment ismade that the multifunctional interface selected by the displayapparatus provided with the front seat is the same as the contents whichare being displayed on the screen of the display apparatus provided withthe rear seat. In this case, the message is displayed on the screen ofone of the display apparatuses. However, a predetermined symbolindicative of the massage, a predetermined icon indicative of themessage, or the like may be displayed on the screen of one of thedisplay apparatuses.

When, for example, the instruction to the display controlling apparatus100 to output the contents about the multifunctional interface is issuedby the operating unit of the display apparatus provided with the frontseat, the display controlling apparatus 100 is operated to output thecontents about the multifunctional interface to the display apparatusprovided with the front seat, and to allow the display apparatusprovided with the front seat to display the information about the factthat the multifunctional interface selected by the display apparatusprovided with the front seat is the same as the contents which are beingdisplayed on the screen of the other of the display apparatuses. Here,each of the contents may be selected by a pointer or a cursorsuperimposed on the screen of each of the display apparatuses. Thedisplay controlling apparatus may be controlled by a remote controllingunit.

The display controlling apparatus 100 is operative to output thecontents to the display apparatuses on the basis of the prioritysequence assigned to each of the display apparatuses. The followingdescription will be then directed to the case that the operation isperformed by the display controlling apparatus 100 on the basis of thepriority sequence assigned to three display apparatuses “A”, “B”, and“C” electrically connected to the display controlling apparatus 100.Here, the priority order of the display apparatus “A” is high incomparison with the priority order of each of the display apparatuses“B” and “C”. The priority order of the display apparatus “C” is low incomparison with the priority order of the display apparatus “B”.

The display controlling apparatus 100 is operative to allow the contentto be displayed on the screen of the display apparatus “B”, and to beutilized with no restriction even if the judgment is made that thecontent is being displayed on the screen of the display apparatus “B”.On the other hand, the display controlling apparatus 100 is operative toallow the content to be displayed on the screen of the display apparatus“C”, and to be utilized with predetermined restriction while the contentis being displayed on the screen of the display apparatus “B”. When oneor more specific contents are selected by the user, the displaycontrolling apparatus 100 may be operative to judge whether or not toallow the specific contents to be utilized with no restriction. Thepriority sequence of the display apparatus provided with the front seatof the automotive vehicle may be high on one or more specific contentssuch as a navigation of an automotive vehicle in comparison with thepriority of the other display apparatuses. The priority sequence of thedisplay apparatuses may be updated by each of the display apparatuses.Similarly, the priority sequence of the contents may be updated by eachof the display apparatuses.

The following description will be directed to the case that theoperation is performed with the restriction on the use of the contentsto be displayed on the screens of the display apparatuses. The displaycontrolling apparatus is operative to allow the contents to be displayedby the first display apparatus and to be utilized by one of the usersthrough the first display apparatus with the restriction on the use ofthe contents when the judgment is made that the contents selected by theother of the users are the same as the contents which are being utilizedby one of the users. More specifically, the display controllingapparatus may be operative to judge whether or not to allow the user toscroll the viewing area on the basis of the contents displayed on thescreen of the display apparatus.

The following description will be directed to the case that the displaycontrolling apparatus is operated to allow the contents to be displayed,and to be utilized with the restriction when the automotive vehicle ismoving. As shown in FIG. 10(a), the display controlling apparatusaccording to the third embodiment of the present invention is operativeto allow the display apparatus provided with the front seat to forciblydisplay the contents on the navigation on the screen when the judgmentis made that the automotive vehicle is moving. As shown in FIG. 10(c),the display controlling apparatus according to the third embodiment ofthe present invention is operative to allow the display apparatusprovided with the front seat not to forcibly display the contents on thescreen when the judgment is made that the automotive vehicle is moving.

From the above detail description, it will be understood that thedisplay controlling apparatus according to the third embodiment of thepresent invention can allow one of the display apparatuses to display onthe screen the information about the fact that the contents selected byone of the display apparatuses is the same as the contents which isbeing outputted to the other of the display apparatuses.

When the judgment is made that the contents selected by one of thedisplay apparatuses is the same as the contents which is being outputtedto the other of the display apparatuses, the display controllingapparatus according to the third embodiment of the present invention canallow the selected contents to be outputted and displayed on the screenof one of the display apparatus with the information.

The display controlling apparatus according to the third embodiment ofthe present invention can improve the usability of the system by havingeach of the display apparatuses display on its screen the respectivepointer required to point the operation to be performed.

The display controlling apparatus according to the third embodiment ofthe present invention can allow the contents to be displayed by one ofthe display apparatuses and to be utilized by one of the users throughone of the display apparatuses without interruption by reason that thedisplay controlling apparatus is operative to allow the contents to bedisplayed by the other of the display apparatuses and to be utilized bythe other of the users through the other of the display apparatuses withthe restriction on the use of the contents when the judgment is madethat the contents selected by the other of the users are the same as thecontents which are being utilized by one of the users.

The display controlling apparatus according to the third embodiment ofthe present invention can selectively allow the contents to be displayedby the display apparatuses on the basis of the priority sequenceassigned to each of display apparatuses.

The display controlling apparatus according to the third embodiment ofthe present invention can allow the priority sequence assigned to eachof display apparatuses to be updated by the user to improve theusability of the system.

INDUSTRIAL APPLICABILITY OF THE PRESENT INVENTION

In accordance with the present invention, there is provided a displaycontrolling apparatus which can be simple in construction in comparisonwith the conventional apparatus by reason that the controlling unit isoperative to control each of the display apparatuses to have the displayapparatuses simultaneously display the images to be utilized by theusers.

1. A display controlling apparatus, comprising: data outputting units tobe electrically connectable to respective display apparatuses; aninformation inputting unit to be operable to have inputted thereininformation to be required for said display apparatuses to display onscreens; a controlling unit for producing contents to be displayed bysaid display apparatuses from said information inputted by saidinformation inputting unit; and a video memory having stored thereinsaid contents produced by said controlling unit, wherein saidcontrolling unit is operative to output said contents stored in saidvideo memory to said display apparatuses through said data outputtingunits.
 2. A display controlling apparatus as set forth in claim 1, inwhich said controlling unit is operative to adjust the resolution ofeach of said contents to be displayed by said display apparatuses on thebasis of the number of said display apparatuses electrically connectedto said signal outputting units, and to output said contents to bedisplayed at said adjusted resolution by said display apparatusesthrough said data outputting units, and in which said controlling unitis operative to maintain said resolution of each of said contents to bedisplayed by said display apparatuses when the judgment is made thatsaid number of said display apparatuses is equal to one.
 3. A displaycontrolling apparatus, comprising: data outputting units to beelectrically connectable to respective display apparatuses; aninformation inputting unit to be operable to have inputted therein datato be required for said display apparatuses to display on screens; acontrolling unit for producing image data on contents to be displayed bysaid display apparatuses on the basis of said information inputted bysaid information inputting unit; and a video memory having storedtherein said image data produced by said controlling unit, wherein saidcontrolling unit is operative to output said contents to said displayapparatuses through said data outputting units on the basis of saidimage data stored in said video memory.
 4. A display controllingapparatus as set forth in claim 1, in which said image data has layersto be collectively defined as data structure, and in which each of saidcontents to be displayed by said display apparatuses is constituted bydata assigned to one or more of said layers.
 5. A display controllingapparatus as set forth in claim 1, in which said controlling unit isoperative to allow said contents to be sequentially received by saiddisplay apparatuses through said data outputting units in order of saiddata outputting units electrically connected to said display apparatusesin a period of a synchronization signal.
 6. A display controllingapparatus as set forth in claim 5, in which the number of said displayapparatuses electrically connected to said data outputting units isequal to two, and in which said controlling unit is operative to allowsaid contents to be received by one of said two display apparatuses oneach of leading edges of said synchronization signal, and to allow saidcontents to be received by the other of said two display apparatuses oneach of trailing edges of said synchronization signal.
 7. A displaycontrolling apparatus as set forth in claim 1, in which each of saiddisplay apparatuses electrically connected to said data outputting unitshas an operating unit for issuing an instruction to said controllingunit to select one or more contents, and in which said controlling unitis operative to judge whether or not one or more contents selected byone of said display apparatuses are the same as one or more contentswhich are being outputted to the other of said display apparatuses, andto allow one of said display apparatuses to display information onwhether or not one or more contents selected by one of said displayapparatuses are the same as one or more contents which are beingoutputted to the other of said display apparatuses in response to saidinstruction issued by said operating unit of one of said displayapparatuses.
 8. A display controlling apparatus as set forth in claim 1,in which each of said display apparatuses electrically connected to saiddata outputting units has an operating unit for issuing an instructionto said controlling unit to select one or more contents, and in whichsaid controlling unit is operative to judge whether or not one or morecontents selected by one of said display apparatuses are the same as oneor more contents which are being utilized through said operating unit tothe other of said display apparatuses, and to allow one of said displayapparatuses to display information on whether or not one or morecontents selected by one of said display apparatuses are the same as oneor more contents which are being outputted to the other of said displayapparatuses in response to said instruction issued by said operatingunit of one of said display apparatuses.
 9. A display controllingapparatus as set forth in claim 7, in which said information displayedby one of said display apparatuses is represented by a pointer.
 10. Adisplay controlling apparatus as set forth in claim 7, in which saidcontrolling unit is operative to allow one or more contents to beutilized through said operating unit of one of said display apparatuseswith the restriction on the use of said contents after allowing one ofsaid display apparatuses to display said information that one or morecontents selected by one of said display apparatuses are the same as oneor more contents which are being outputted to the other of said displayapparatuses.
 11. A display controlling apparatus as set forth in claim1, in which said display apparatuses each has an operating unit forissuing an instruction to said controlling unit to output one or morecontents, said display apparatuses being assigned to respective prioritysequences, in which said controlling unit is operative to judge whetheror not one or more contents which are being outputted to one of saiddisplay apparatuses are the same as one or more contents selected by theother of said display apparatuses before judging whether or not one ofsaid display apparatuses exceeds in priority sequence the other of saiddisplay apparatuses when the judgment is made that one or more contentsselected by the other of said display apparatuses are the same as one ormore contents which are being outputted to one of said displayapparatuses, and in which said controlling unit is operative to allowthe other of said display apparatuses to display one or more contentsthe same as one or more contents which are being outputted to one ofsaid display apparatuses with the restriction on the utilization of saidcontents when the judgment is made that one of said display apparatusesexceeds in priority sequence the other of said display apparatuses. 12.A display controlling apparatus as set forth in claim 11, in which saidcontrolling unit is operative to allow said priority sequence assignedto each of said display apparatuses to be changed by each of saidoperating unit of said display apparatuses.
 13. A display controllingapparatus for allowing display apparatuses to display respective imagesrepresented by image data, comprising: a multiplexing unit formultiplexing said image data indicative of said images to be displayedby the display apparatuses; a buffer memory having stored therein saidmultiplexed image data; and demultiplexing unit for demultiplexing saidmultiplexed image data stored in said buffer memory to output saiddemultiplexed image data to each of said display apparatuses.
 14. Adisplay controlling apparatus as set forth in claim 13, which furthercomprises: a synchronization signal producing unit for producing asynchronization signal to be constituted by a pulse string having apredetermined period, and in which said demultiplexing unit is operativeto demultiplex said multiplexed image data stored in said buffer memoryby allowing said multiplexed image data to be selectively received byeach of said display apparatuses in said predetermined period of saidsynchronization signal.
 15. A display controlling apparatus as set forthin claim 13, which further comprises: a synchronization signal producingunit for producing a synchronization signal to be constituted by a pulsestring having a predetermined period, and in which said demultiplexingunit is operative to demultiplex said multiplexed image data stored insaid buffer memory by allowing said multiplexed image data to bereceived by one of said two display apparatuses on each of leading edgesof said synchronization signal, and to be received by the other of saidtwo display apparatuses on each of trailing edges of saidsynchronization signal.
 16. A display controlling apparatus as set forthin claim 13, in which said multiplexing unit is operative to adjust saidresolution of each of said images to be respectively displayed by thedisplay apparatuses on the basis of the number of said displayapparatuses electrically connected to said data outputting units tomultiplex image data indicative of said images to be respectivelydisplayed by the display apparatuses at said adjusted resolution.
 17. Adisplay controlling apparatus as set forth in claim 16, in which saidmultiplexing unit is operative to adjust said resolution of each of saidimages to be respectively displayed by the display apparatuses ininverse proportional relationship with the number of said displayapparatuses electrically connected to said data outputting units.